Conduit-threader.



I J. G. DIETER, S. BOWSHER 6a E. DAVIS.

GONDUIT THEADER.

APPLICATION FILED 111111.11, 1907.

Patented 001.13, 1908.

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UNITED sTArEsieArENr oEEicE.

JOHN C. DIETER, OF ANDERSON, AND SAMUEL BOWSHER, OF INDIANAPOLIS, INDIANA, AND

ENZLEY DAVIS, OF TOLEDO, OHIO.

CONDUIT-THREADER.

To all 'whom it may concern:

Be it known that we, JOHN C. DIETER, a citizen ofthe United States, residing at An derson, county of Madison, State of Indiana, and SAMUEL BowsHEn, a citizen lof the United States, residing at Indianapolis, in the county of Marion and State of Indiana, and ENZLEY DAvis, a citizen of the United States, residing at Toledo, in the county of Lucas and State of Ohio, have invented certain new and useful Improvements in Conduit-Threaders; and we do declare the following to be a full, clear, and exact descrip tion of the invention, such as will enable others skilled in the art to which it appertains to make anduse the same.

This invention relates to conduit threaders, and has for its object to provide a device of this kind, by means of which the work can be quickly done and at a comparatively small cost. i

The purpose of the invention is to draw a cord or thread through the conduit, the cord being used to draw a rope through, and the rope in turn being used to pull a cable through. y

The present method of threading conduits is by the use of four-foot joined rods, which are successively joined together as they are inserted into the'conduit, runtil the opposite end of the conduit is reached, when the rods are successively uncoupled and removed. A rope is secured to the last section and isy pulled through the conduit, by means of the rod, the rope in turn being used to pull the cable through. This method is slow, and as can readily be seen, veryexpensive.

In the accompanying drawings, which illustrate the invention, Figure 1 is a longitudinal sectional view of a portion of a conduit within which is located the threader; Fig. 2 is an enlarged view of one of the rollers, and the means for supporting it, Fig. 3 is an end view of the ratchet mechanism uponione end of the roller. Fig. 4L is an enlarged longitudinal sectional view of'the adjacent ends of the hollow rods or members; and Figs. 5, 6 and 7 are detail views of modifications. j

Referring more particularly to the drawings, which are for illustrative purposes only, and are not therefore drawn to scale, A and B indicate two hollow rods, which are'telescopically secured together' and adapted tov be moved in one' direction by means of a Specification of Letters Patent.

Application filed March 11, 1907.l Serial No. 361,817.

Patented Oct. 13, 1908.

spring C, which is coiled around the rods and has its forward` end securedto the rod fr and the rear end secured to the rod B. The rear end of the rod A is preferably provided with a reduced portion D which is adapted to be' secured thereto in any suitable manner, as by screw-threads, and the forward end of the rod B is provided with a collar E to prevent the accidental separation of the rods.

The forward end of the outer rod A is provided with two rollers F and Gr, which are journaled in the outer ends of yielding arms H and I, respectively, the inner ends of said arms beingVV secured to the rod in any suitable manner, as by means of screws J. Corresponding rollers K and L are secured to the rod B near its rear end, by means of 4similar arms M and N, respectively. The supporting arms `are preferably extended to the rear so that as the machine moves forward the rollers will more readily pass over any obstruction or inequality that may be met with in the conduit.

Shoes O and P are secured tothe under sides ofthe rods so as to support the threader substantially axially within the conduit and thereby cause Vthe upper rollers to always engage with the upperside of the conduit and cause the machineto move forward when it is operated.

\ A roller Q, is journaled in the forward end of the inner or smaller rod B over which is passed a cord B, one end of which is secured to the rear end of the outer rod A, and after being passed forward over the roller Q is extended back through the rod B, and projects therefrom in position to be grasped by the operator and drawn back whenever it is desired to actuate the threader.

As above described, it is evident that when the two rods A and B occupy their proper or normal positions relatively to each other, the forward end of the rod B will be projected into the rod A nearly to its forward end. Now by pulling upon the cord R, the rods will be moved outward relatively to each other, and by fastening the rear rod B against rearward movement the outer or forward rod A will be forced forward to a distance equal to half the length of the cord that is drawn backward. As soon as the cord R is released, the strain which has been placed upon the spring C by this movement of the rods will immediately cause'the rods to move in the opposite direction, or be telescoped into their normal positions with the forward end of the inner rod near the forward end of the outer rod, and will also draw in the cord ready to be drawn backward again.

By holding the outer rod against rearward movement during the contraction of the spring, the inner rod will be drawn forward. into its normal position, after which, a repetition of pulling' upon the cord will cause the threader to move through the conduit step by step until it reaches the farther end, where it can be removed and the cable drawn through in the usual manner.

The locking of the rods against rearward movement is best secured by providing each of the rollers that engage with the conduit with a pawl S which is adapted to engage with shoulders T similar to the action of curtain rollers, and the engagement of the rollers with the conduit is insured by roughening or corrugating the surface of the rollers, preferably by providing' each roller with a corrugated shell or cylinder U which is secured thereon by means of one or more small screws V. The periphery of the rollers may be provided with teeth lV, as shown more clearly in the drawings, or the cylinder may be formed from rubber or other suitable material as shown at X in Fig. Or the rollersmay be omitted entirely and the ends of the legs or supports can engage with the wall of the conduit direct as shown at Y in Fig; 6, their tips or ends being preferably pointed for this purpose. Or they may be left blunt and covered with rubber as at Z in Fig. 7 to insure their engagement with the wall of the conduit.

The length of the machine may also be made adjustable by making it in sections as shown in Fig. G and a second cord lt in Fig. (i may be provided for engaging with the legs and collapsing' them or bending them inward so that the device can be drawn backward out of the conduit in case it should be impossible for it to be passed through the conduit as by becoming inoperative from any cause.

Having claim In a conduit threader two telescopio hollow members the rear end of the outer one having a reduced member to [it the inner member and the inner end of the inner one having a collar to tit the interior of said outer member, a coil spring surrounding and secured at its ends to said members. support ing shoes for each member, rearwardly extending' flexible arms on said members, rollers mounted on said arms and havingl frictional engaging surfaces, a ratchet wheel on each of said rollersj a pawl for engaging said ratchet wheel to prevent retrogrmle movement of said rollers, and means 'tor moving said members against the tension of the spring.

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

JOHN C. Dllllllllll. SAMUEL BOiVSl l ltllt. ENZLEY DAVIS. iVitnesses to the signatures of J'. C. l.)ieter and Samuel Bowsher:

MONROE llUNrZiNenn, A. J. ArrLneivrn. iVitnesses to the signature of l1). Davis:

A. R. MCCaNDLisn L. M. MolLwANE.

described our invention, we 

